Medical device with hydrophilic coating

ABSTRACT

A urinary catheter having an insertable shaft formed from a blend of an ethylene and/or propylene based polymer and water swellable material. The catheter having a hydrophilic coating disposed on the outer surface of the insertable catheter shaft.

The present application is a U.S. National Stage of PCT InternationalPatent Application No. PCT/US2017/018073, filed Feb. 16, 2017, whichclaims the benefit and priority of U.S. Provisional Patent ApplicationNo. 62/298,728, filed Feb. 23, 2016, both of which are herebyincorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to medical devices which have a substrateincluding a hydrophilic coating thereon. More particularly, the presentdisclosure relates to medical devices for insertion into a body and,even more particularly, medical devices for insertion into lumens orpassageways of the body, e.g., urinary catheters and endoscopes. Thepresent disclosure also relates to methods of using and making suchmedical devices.

BACKGROUND

In the medical field, and in other fields as well, the surface of adevice may be coated with a hydrophilic coating that becomes lubriciousupon contact with water to ease insertion of the device into the body.Such lubricious hydrophilic coatings may be disposed on urinarycatheters, vascular catheter, catheter guide wires, and other medicaldevices that are meant to be inserted into the body. The lubriciousnature of such materials allows the insertion (and subsequent removal)of a catheter or other medical device to be accomplished with minimumresistance, thereby reducing discomfort and possible injury.

While the use of lubricious hydrophilic coatings on medical devices isbecoming more common, it remains difficult to prepare a lubricioushydrophilic coating that securely attaches to the substrate surface.Secure attachment of the lubricious coating to the substrate surface isgenerally desirable and particularly useful in the medical field, wheresecure attachment of the coating is often an important requirement.

In many instances, securing the hydrophilic coating to a substratesurface includes the use of primer layer or tie layer that has goodattachment to both the substrate surface and the hydrophilic layer. Whena primer layer is employed, the primer layer is disposed or coated ontothe surface of the medical device, after which the top hydrophiliccoating is disposed on the primer layer. The primer layer attaches toboth the substrate surface and the hydrophilic layer to securely attachthe hydrophilic layer to the substrate. While the use of a primer layermay provide sufficient attachment of the hydrophilic coating, such usemay be undesirable because it requires the use of an extra coating layerand additional steps and time in the preparation and manufacture of themedical device.

Therefore, there is a need for medical devices that have a hydrophiliccoating securely anchored directly to the surface of the substrate ofthe medical device without the use of a primer layer.

BRIEF SUMMARY

There are several aspects of the present subject matter which may beembodied separately or together in the devices and systems described andclaimed below. These aspects may be employed alone or in combinationwith other aspects of the subject matter described herein, and thedescription of these aspects together is not intended to preclude theuse of these aspects separately or the claiming of such aspectsseparately or in different combinations as set forth in the claimsappended hereto.

In one aspect, a urinary catheter includes a catheter tube wherein atleast a portion of the catheter tube is made from a blend of an ethyleneand/or propylene based polymer and a water-swellable polymer. Thecatheter also includes a hydrophilic coating disposed on at least aportion of an outer surface of the catheter tube. The ethylene and/orpropylene based polymer may have a density less than or equal than 0.95g/cm³. Additionally, the outer surface of the catheter tube may have asurface energy of at least about 30 mN/m.

In another aspect, a urinary catheter includes a catheter tube whereinat least a portion of the catheter tube is made from a blend of anethylene and/or propylene based polymer and a water-swellable material.

In yet another aspect, a method of making a urinary catheter thatincludes the step of blending an ethylene and/or propylene based polymerwith a water swellable material to form a blend. The blend is formedinto a urinary catheter tube having an outer surface and a hydrophiliccoating is disposed on the outer surface.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a graph representing the spectrum of the light utilized tocure and dry the coating in the Examples.

DETAILED DESCRIPTION

While the subject matter of the present disclosure is susceptible toembodiments in various forms, there will hereinafter be describedpresently preferred embodiments with the understanding that the presentdisclosure is to be considered an exemplification and is not intended tolimit the disclosure to the specific embodiments illustrated. The words“a” or “an” are to be taken to include both the singular and the plural.Conversely, any reference to plural items shall, where appropriate,include the singular.

The present disclosure is directed to lubricious medical devices thatinclude a lubricous hydrophilic coating disposed on the outer surface ofthe substrate of the medical device to enhance the lubricity of themedical device so as to ease the insertion of the device into the bodyand reduce discomfort during insertion and remove of the device. Themedical devices include a substrate that is made from a blend or mixturethat includes an ethylene and/or propylene based polymer and one or morewater swellable materials, such as water swellable polymers. As usedherein, the term “polymer” is inclusive of homopolymers and copolymers.The blend also may include other compositions and/or additives, such ascompatibilizers/stabilizers.

The lubricious hydrophilic coating may be disposed directly on andadhered directly to the outer surface of the substrate. The surface ofthe substrate may be a non-treated surface in that the surface is notpre-cleaned with solvents and/or pretreated with plasma, corona, etc.prior to forming the hydrophilic coating on the surface of thesubstrate. The blend of ethylene and/or propylene based polymer and awater swellable material provides a substrate surface to which thelubricous hydrophilic coating is sufficiently secured without the needfor a primer layer. In one embodiment, the lubricous hydrophilic coatingis secured directly to the substrate surface without any covalentbonding between the coating and the substrate surface and/or without theformation of an interpenetrating polymer network between the coating andthe substrate surface. In one embodiment, the substrate surface includespolar groups that are capable of bonding with the hydrophilic coating toform sufficient attachment without covalent bonding and/or aninterpenetrating polymer network.

Although pre-treatments and/or a primer layer may not be necessary, inother embodiments, the lubricious hydrophilic coating may be applied andadhered to the outer surface of the substrate that has been pretreatedand/or with the use of a primer layer.

The medical devices of the present disclosure may be, for example, thosethat are configured for insertion into a lumen of a human body, such asthe urethra, fallopian tubes, nasal passages or esophagus. Such medicaldevices may include, but are not limited to, urinary catheters andendoscopes. While the subject matter disclosed herein may be describedrelative to urinary catheters, the subject matter is not limited to suchand such subject matter may apply to other suitable medical devices aswell.

Urinary catheters typically include a catheter tube or shaft that has aninsertable portion that is inserted through the urethra and into thebladder to drain urine therefrom. The catheter tube may include aproximal end portion which is inserted through into and through theurethra and into the bladder. The proximal end portion may have drainageeyes or holes that allow urine to drain out of the bladder and into andthrough the catheter tube. The catheter tube also includes a distal endportion that may have a drainage element, such as a funnel, associatedtherewith to drain the urine into a collection container, such as atoilet or waste collection bag.

In one embodiment of a urinary catheter of the present disclosure, thecatheter includes a catheter tube, i.e. a substrate, having an outersurface that is at least partially coated with a lubricious hydrophiliccoating. The lubricous hydrophilic coating is in direct contact with theouter surface of the catheter tube without the use of a primer layerbetween the outer surface of the catheter tube and the lubricoushydrophilic coating. Preferably, the substrate surface of the cathetertube includes polar groups that are capable of bonding with thehydrophilic coating to sufficiently attach the coating to the surface ofthe catheter tube without covalent bonding and/or an interpenetratingpolymer network between the coating and the surface of the cathetertube.

The catheter tube may be made from a polymer blend or mixture thatincludes an ethylene and/or propylene based polymer and awater-swellable material, such as a water swellable polymer. In oneembodiment, the ethylene and/or propylene based polymer has a density ofless than or equal to 0.95 g/cm³. The reduced density of the polymer maybe due to, for example, a hindering of crystalline structure. Suchpolymers may include, for example, ethylene based olefin plastomers,such as copolymers of ethylene and an alpha-olefin which hinderscrystalline structure. The alpha-olefin may be, for example, 1-butene,1-hexene or 1-octene. In one embodiment, the polymer may be an ethylenebased 1-octene plastomer. One exemplary commercially available polymerhaving a density less than or equal to 0.95 g/cm³ is Queo™ 8210,supplied by Borealis, Vienna Austria. Other commercially availableproducts may include, for example, Mitsui Chemicals Tafmer DF840, Dow'sVersify elastomers and plastomers such as Versify 2300 and Versify 3300,Dow's Attane 4404G, Ateva 2820A, Madalist MD575, Medalist MD585 and/orother styrene ethylene butylene styrene (SEBS) thermoplastic elastomers.

As used herein the term “water swellable material” refers to materialsthat swell in the presence of water. Generally, any water swellablematerials or mixtures thereof could be used in the blend. Preferably,the water swellable material contained in the blend is a material thatswells in water but will not swell to the point of destroying thedimensions and/or functionality of the medical device. In other words,the material will swell while maintaining the dimensional stabilityand/or functionality of the medical device. In one embodiment, the waterswellable materials are those that swell in water but do not swell morethan 50% of their original non-swollen weight when in contact with waterat 25° C. for a period of 1 hour. Suitable water-swellable materialsinclude but are not limited to water swellable ethylene basedcopolymers, water swellable polyamide-based copolymers, water swellablepolyester-based copolymers, water swellable polyether based copolymers,water swellable urethane-based copolymers, and mixtures thereof. Any ofa variety of thermoplastic polymers, thermoplastic elastomers, and/orthermoplastic alloys, which are capable of swelling in the presence ofwater, may be used. Preferably, the water swellable materials areextrusion grade. Water swellable polymers may include, for example,ethylene vinyl alcohol copolymer, polyvinyl alcohol, polyether blockamide and thermoplastic polyurethanes. For example, the water swellablepolymer may be ethylene vinyl alcohol. The ethylene vinyl alcohol mayhave between about 20 wt % and about 50 wt % ethylene and about 50 wt %to about 80 wt % vinyl alcohol.

In one embodiment, the ethylene and/or propylene based polymer may bebetween about 5 wt % and about 95 wt % of the blend and the waterswellable material may be about 95 wt % and about 5 wt % of the blend.Preferably, the ethylene and/or propylene based polymer may be betweenabout 80 wt % and about 95 wt % of the blend and the water swellablematerial may be about 20 wt % and about 5 wt % of the blend. Morepreferably, the ethylene and/or propylene based polymer may be about 90wt % of the blend and the water swellable material may be about 10 wt %of the blend.

Optionally, the blend may also include a compatibilizer that may promoteinterfacial adhesion and stabilization between the ethylene and/orpropylene based polymer and water swellable polymer. In one embodiment,the compatibilizer may be an acid modified polyolefin, such as anacrylic acid modified polyolefin. For example the blend may includebetween about 5 wt % and 20 wt % of the compatibilizer. In oneembodiment, the blend may include ethylene and/or propylene basedpolymer in an amount between about 70 wt % and about 90 wt % of theblend, a water swellable polymer or copolymer in an amount of betweenabout 20 wt % and 5 wt % of the blend, and a compatibilizer in an amountof between about 10 wt % and about 5 wt %.

In one embodiment, a substrate (e.g., a catheter or other medicaldevice) is formed from an ethylene and/or propylene based polymer andwater swellable polymer blends wherein the surface of the substrateincludes polar groups capable of bonding to a hydrophilic coating. Suchpolar groups include for example, hydroxyl groups, carboxyl groups,ether groups and amide groups. Preferably, the surface of the substrateis capable of forming polar bonds with the hydrophilic coating such thatthe coating is sufficiently attached to the substrate surface withoutthe formation of covalent bonds and/or an interpenetrating polymernetwork between the substrate surface and the hydrophilic coating. Inone embodiment, the surface energy of the substrate surface is at least30 mN/m. In one example, at least a portion of a substrate, such as acatheter tube or other medical device, is made from a blend of anethylene and/or propylene based polymer having a density less than orequal to 0.95 g/cm³ and a water-swellable polymer. The substrate alsohas a surface that has a surface energy of at least 30 mN/m and includespolar groups capable of bonding to a hydrophilic coating, and preferablycapable of forming sufficient attachment of the coating to the substratesurface without the formation of covalent bonds and/or aninterpenetrating polymer network.

Turning to the hydrophilic coating disposed on the outer surface of thecatheter tube. The hydrophilic coating includes a hydrophilic polymercapable of providing hydrophilicity to the coating and lubriciousnesswhen the coating is hydrated. The polymer may be synthetic orbio-derived and can be blends or copolymers of both. Suitablehydrophilic polymers include but are not limited to poly(lactams), forexample polyvinylpyrollidone (PVP), polyurethanes, homo- and copolymersof acrylic and methacrylic acid, polyvinyl alcohol, polyvinylethers,maleic anhydride based copolymers, polyesters, vinylamines,polyethyleneimines, polyethyleneoxides, poly(carboxylic acids),polyamides, polyanhydrides, polyphosphazenes, cellulosics, for examplemethyl cellulose, carboxymethyl cellulose, hydroxymethyl cellulose, andhydroxypropylcellulose, heparin, dextran, polysacharrides, for examplechitosan, hyaluronic acid, alginates, gelatin, and chitin, polyesters,for example polylactides, polyglycolides, and polycaprolactones,polypeptides, for example collagen and fibrins.

In one embodiment, the hydrophilic polymer coating may includepoly(lactams), for example polyvinylpyrollidone (PVP), polyurethanes,homo- and copolymers of acrylic and methacrylic acid, polyvinyl alcohol,polyvinylethers, maleic anhydride based copolymers, polyesters,vinylamines, polyethyleneimines or polyethyleneoxides. Preferably, thehydrophilic polymer coating comprises polyvinylpyrrolidone (PVP).

The hydrophilic polymer may have weight average molecular weight (Mw)from about 20,000 to about 1,300,000, and preferably in the range ofabout 300,000 to about 400,000. Additionally, the amount of hydrophilicpolymer in the coating may be between about 90 wt % and about 98 wt % ofthe total dry weight of the dry coating.

The hydrophilic coating may be applied to the catheter surface in theform of a solution or a dispersion including a liquid medium(hydrophilic coating composition/formulation), which is dried or curedafter the liquid medium has been deposited on the catheter. For example,the hydrophilic coating formulation wets the surface of catheter andthen is exposed to UV light to cure the formulation and form thecoating. The liquid medium may be any suitable medium that allowsapplication or wetting of the hydrophilic coating formulation on thesurface of the substrate. Such liquid media may include water, alcohols,for example methanol, ethanol, propanol, butanol and aqueous mixturesthereof or acetone, methyl ethyl ketone, tetrahydrofuran,dichloromethane, toluene, and aqueous mixtures or emulsions thereof.

The hydrophilic coating may additionally include various additives suchas dispersing and stabilizing agents (surfactants or emulsifiers),antioxidants, photoinitiator and curing agents, such as UV curingagents.

For example, the hydrophilic coating formulation may include, in dryweight percentages, about 95 wt % to about 98 wt % a hydrophilic polymerand about 2 wt % to about 5 wt % photoinitiator and/or other additives.In the topcoat solution, the total solid contents may be about 3 wt % toabout 8 wt % of the solution.

In one embodiment of making a catheter, the ethylene and/or propylenebased polymer and water swellable materials, and optionally additives,are compounded. The blend may be compounded, for example, in a twinscrew extruder. The compounding may take place at temperatures in therange of about 180° C.-200° C. The compounded blend may then be cooledfrom the melt in a water bath at room temperature. The cooled blend isthen pelletized. The pelletized blend may then be dried. For example,the drying may be for 4-6 hours at 35° C. The pelletized blend may beused to form catheters by any suitable process, such as by injectionmolding or extrusion.

The hydrophilic coating may then be applied to the catheter. Thehydrophilic coating may be applied in suitable manner. For example, thehydrophilic coating may be applied by dip coating, brushing or spraying.After the coating is applied, the coating is cured by, for example, UVcuring.

EXAMPLES Materials

Unless otherwise stated, the following materials were used in theExamples described below.

-   -   Ethylene based polymer (EBP) supplied by Borealis, Vienna        Austria, under the name QUEO™ 8210.    -   Polyether block amide (PEBAX) supplied by Arkema, Colombes        France, under the name PEBAX MV1074.    -   Polyvinyl alcohol (PVOH) supplied by Kuraray, Tokyo Japan, under        the name Mowiflex TC 661.    -   Polyvinylpyrrolidone (PVP) 90K supplied by Fluka.    -   Ethylene vinyl alcohol (EVAL) supplied by EVAL Europe, under the        name EVAL.    -   Acid modified polyolefin (Tafmer) supplied by Mitsui Chemicals,        Dusseldorf Germany, under the name Tafmer MA9015.    -   Thermoplastic polyurethane (TPU) supplied by Lubrizol Corp.,        Belper England, under the name Tecophilic HP93A100.    -   Benzophenone supplied by Sigma Aldrich.    -   Alpha-hydroxy ketone supplied by Lamberti, Italy, under the name        Esacure One.

Example 1

Substrates A-C were made from polymer blends A-C which include EBP andPEBAX in the ratios listed in Table 1.

TABLE 1 Substrate Blend A Blend A - 90 wt % EBP:10 wt % PEBAX B BlendB - 80 wt % EBP:20 wt % PEBAX C Blend C - 70 wt % EBP:30 wt % PEBAX

Blends A-C were made by compounding EBP and PEBAX, in the aboverespective ratios, in a twin screw extruder to form the polymer blend.The EBP and PEBAX were compounded at temperatures in the range of about180° C.-200° C. The compounded polymers where cooled from the melt in awater bath at room temperature and pelletized. The pelletized blendswere dried for 4-6 hours at 35° C. An injection molding machine was usedto form each of the respective pelletized blends into dog bone shapedsubstrates A-C.

An EBP only substrate, substrate D, was made by injection moldingpelletized EBP into a dog bone shape.

The tensile mechanical properties of each of the substrates A-D werecharacterized using an Instron testing machine. The average modulus foreach substrate was calculated from the testing of five samples and islisted in Table 2 below.

TABLE 2 Substrate Modulus [MPa] A 9.8 B 17.2 C 22.8 D 9.1

Water uptake measurements were obtained by placing substrates A-C inwater at room temperature. Weight measurements of the substrates wheretaken at the time intervals listed below in Table 3. The average percentof weight gain as a function of time was calculated from testing fivesamples of each substrate and is reported in Table 3.

TABLE 3 Days 0 6 13 21 72 Water Water Water Water Water Substrate uptake% uptake % uptake % uptake % uptake % A 0 0.91 1.29 1.58 1.72 B 0 2.573.51 4.18 4.52 C 0 4.96 6.59 7.67 8.25

The tensile mechanical properties of substrates A-D were measured afterthe substrate was immersed in water for a period of 6 days and gammairradiated with a dose in the range between about 25 kGy and about 40kGy. The average of the tensile modulus of the wet irradiated substrateswas calculated from five samples of each substrate and is reported inTable 4.

TABLE 4 Wet Irradiated Modulus Substrate [MPa] A 3.1 B 6.6 C 10.4 D 9.5

Example 2

Substrates E-G were made from polymer blends E-G which include EBP andPVOH in the ratios listed in Table 5.

TABLE 5 Substrate Blend E Blend E - 90 wt % EBP:10 wt % PVOH F Blend F -20 wt % EBP:20 wt % PVOH G Blend G - 70 wt % EBP:30 wt % PVOH

Blends E-G were made by compounding EBP and PVOH, in the aboverespective ratios, in a twin screw extruder to form the polymer blend.The EBP and PVOH were compounded at temperatures in the range of about180° C.-200° C. The compounded polymers where cooled from the melt in awater bath at room temperature and pelletized. The pelletized blendswere dried for 4-6 hours at 35° C. An injection molding machine was usedto form each of the respective pelletized blends into dog bone shapedsubstrate E-G.

The tensile mechanical properties of each of the substrates E-G werecharacterized using an Instron testing machine. The average modulus foreach substrate was calculated from the testing of five samples and islisted in Table 6 below.

TABLE 6 Substrate Modulus [MPa] E 14.3 F 25.5 G 43.3

Water uptake measurements were obtained by placing substrates E-G inwater at room temperature. Weight measurements of the substrates wheretaken at the time intervals listed below in Table 7. The average percentof weight gain as a function of time was calculated from testing fivesamples of each substrate and is reported in Table 7.

TABLE 7 Days 0 6 13 21 72 Water Water Water Water Water Substrate uptake% uptake % uptake % uptake % uptake % E 0 1.88 2.87 3.62 4.00 F 0 3.585.33 6.66 7.39 G 0 6.65 9.78 12.35 13.88

The tensile mechanical properties of substrates E-G were measured afterthe substrate was immersed in water for a period of 6 days and gammairradiated with a dose in the range between about 25 kGy and about 40kGy. The average of the tensile modulus of the wet irradiated substrateswas calculated from five samples of each substrate and is reported inTable 8.

TABLE 8 Wet Irradiated Modulus Substrate [MPa] E 7.0 F 10.8 G 11.5

Example 3

Each of the pelletized blends A-C from Example 1 and E-G from Example 2above were injection molded to form tubular urinary catheters A-C andE-G, respectively. Each of the catheters had a length of 95 mm anddrainage eyes in the proximal end portion of the catheter. A hydrophiliccoating was applied directly to the outer untreated surface (no washingwith solvent or treating with plasma, corona etc.) of each of thecatheters by dip coating. The hydrophilic coating included about 5 wt %polyvinylpyrrolidone and about 0.1 wt % benzophenone in the coatingsolution. The polyvinylpyrrolidone and benzophenone were dissolved in asolvent including a mixture of water/isopropyl alcohol. The ratio ofwater to isopropyl alcohol in the solvent was 30:70, and the solvent wasat about 94.9 wt % and the dissolved polyvinylpyrrolidone andbenzophenone were at about 5.1 wt %. To coat each of the catheters, thecatheters were immersed in the coating for 90 seconds and then retractedfrom the coating at 0.9 cm/s. The catheters with the coating thereonwere exposed to electromagnetic radiation for 10 minutes to deliver adose sufficient to cross-link the coating and remove the solvent. Thespectrum of the electromagnetic radiation utilized to cross-link thecoating is shown in FIG. 1 and was measured in the range 200-800 nm witha Hamamatsu UV/vis mini spectrometer model C10082MD.

Initial and abraded coefficient of friction (CoF) were measured for eachof the coated catheters A-C and E-G. To measure both the initial andabraded CoF, CoF was measured using a Harland Friction Tester ModelFTS5500. During the CoF measurement, the proximal end portion of thecatheter is cut (13 mm from the tip end of the catheter) and a mandrelwas inserted into the remaining section of the coated catheter of thecoated catheter tube. The tube was then clamped between two pieces ofsilicone rubber at 100 g load wherein the silicone rubber had a Shorehardness of 60 A. The tube with the mandrel inserted therein was pulledthrough the two pieces of silicone rubber at a speed of 10 mm/s. Theforce required to pull about 40 mm of the tube through the two pieces ofsilicone rubber was measured and recorded using a universal tensiletester equipped with a 200 N load cell. The CoF value was calculatedfrom the ratio of recorded to applied loads (i.e., the recorded loaddivided by 2 times the applied load or 200 g) when steady state wasreached.

To measure the initial CoF, the coated catheters A-C and E-G wereimmersed in water for 30 seconds prior to conducting CoF testing in theabove-identified manner. For the abraded CoF measurements, catheters A-Cand E-G were placed in a water bath and abraded 50 times by passing thecatheter tubes back and forth 25 times through 4.14 mm diameter hole ina 1 mm thick silicone pad with Shore hardness of 60 A. The abrading tookplace while the catheter was immersed in the water bath. This test isdesigned to remove any portions of the coating that are not well adheredto the catheter. The CoF of the abraded catheters were measured in theabove-described manner.

Table 9 shows a summary of the CoF results for catheters A-C and E-F.CoF testing was not performed on catheter G because the surfaces of themolded parts were irregular and not coated. In cases A-C and E-F, theabraded CoF is low, indicating the coating is well anchored onto thecatheter substrate without the need of a Primer coating.

TABLE 9 Catheter Initial CoF Abraded CoF A 0.0191 0.0224 B 0.0412 0.0288C 0.0310 0.0279 E 0.0225 0.0231 F 0.0269 0.0253 G N/A N/A

Example 4

Tubing samples H-N were made from the blends shown in Table 10 below.

TABLE 10 Tubing Sample Blends H Blend H - 98 wt % EBP:2 wt % PVOH IBlend I - 90 wt % EBP:10 wt % PVOH J Blend J - 80 wt % EBP:20 wt % EVALK Blend K - 90 wt % EBP:10 wt % EVAL L Blend L - 90 wt % EBP:10 wt % TPUM Blend M - 85 wt % EBP:10 wt % PEBAX:5 wt % Tafmer N Blend N - 90 wt %EBP:10 wt % PEBAX

Each of the blends H-N was made by compounding the above listedrespective components for each blend in a twin screw extruder to thepolymer blends. The components were compound at temperatures in therange 180° C.-200° C. using a twin screw extruder. Each of thecompounded blends was cooled from the melt in a water bath at roomtemperature and pelletized into polymer chips. The pelletized blendswere dried for 4-6 hours at 35° C. prior to tube extrusion. Each of thepelletized blends was then extruded into tubes. Each of the tubes H-Nhad inner and outer diameters of 3.1+/−0.1 mm and 4.6+/−0.13 mm,respectively.

Surface Energy Measurements

Surface energy measurements were carried out on each of tubes H-N. Themeasurements were carried out with Arcotest test pens. Eight pens wereused in the ranged from 30-44 mN/m wherein the pens differed in 2 mN/mincrements (30, 32, 34, etc.). The accuracy of the pens were +/−1 mN/m.The surface energy measurements were taken by marking a piece of thetubing with the pen having an ink with surface tension of 30 mN/m. Theink mark was then observed to determine if the pen's ink wets thesurface of the tube or if it de-wets forming droplets of liquid onto thesurface. If the ink wetted the surface, it was concluded that thesurface energy of the tube is greater than or equal than 30 mN/m. If theink de-wetted the surface, it was concluded the surface energy of thetube is less than 30 mN/m. If the ink wetted the surface, then the nextink having surface tension of 32 mN/m was utilized to evaluate thesurface energy of the tube. This procedure was continued until thesurface energy of the tube is obtained.

TABLE 11 Surface Tubing Energy Sample [mN/m] H <30 I 30 J 30 K 30 L 30 M30 N <30

Hydrophilic Coating

Each type of tubing sample H-N was coated with a hydrophilic coatingwithout using a primer coating/layer and without pre-treating thesurface of the tubing (without pre-treating with a solvent, plasma,corona, etc.). The hydrophilic coating was applied directly to thesurfaces of the catheters by dip coating. The hydrophilic coatingincluded about 5% wt % polyvinylpyrrolidone and about 0.1 wt %benzophenone or about 0.1 wt % Esacure One. The polyvinylpyrrolidone andbenzophenone or Esacure One were dissolved in a solvent including amixture of water/isopropyl alcohol. The ratio of water to isopropylalcohol in the solvent was 30 wt % water to 70 wt % isopropyl alcohol,and the solvent was at about 94.9 wt % and the dissolvedpolyvinylpyrrolidone and benzophenone or Esacure were at about 5.1 wt %.To coat each of the tubes, the tubes were immersed in the coating for 90seconds and then retracted from the coating at 0.9 cm/s. The tubes withthe coating thereon were exposed to electromagnetic radiation for 10minutes to deliver the dose required to cross-link the coating andremove the solvent. The spectrum of the electromagnetic radiationutilized to cross-link the coating is shown in FIG. 1 and was measuredin the range 200-800 nm with a Hamamatsu UV/vis mini spectrometer modelC10082MD.

Initial, abraded and dry-out coefficients of friction (CoF) weremeasured for each of the coated tubes H-N. A Harland Friction TesterModel FTS5500 was used to measure both the initial and abraded CoF. Theprocedure for measuring CoF includes inserting a mandrel into a 127 mmsection of the coated tubing. The tubing was then clamped between twopieces of silicone rubber at 100 g load wherein the silicone rubber hada Shore hardness of 60 A. The tubing with the mandrel inserted thereinwas pulled through the two pieces of silicone rubber at a speed of 10mm/s. The force required to pull about 80 mm of the coated tubingthrough the two pieces of silicone rubber was measured and recordedusing a universal tensile tester equipped with a 200 N load cell. TheCoF value was calculated from the ratio of recorded to applied loads(i.e., the recorded load divided by 2 times the applied load or 200 g)when steady state was reached.

For the initial CoF measurement, the coated tubings were immersed inwater for 30 seconds prior to CoF testing. For the abraded CoFmeasurements, the coated tubings were placed in a water bath and abraded50 times by passing the catheter tubes 25 times back and forth through4.14 mm diameter hole in a 1 mm thick silicone pad with Shore hardnessof 60 A. The abrading took place while the catheter was immersed in thewater bath. This test is designed to remove any portions of the coatingthat are not well adhered to the catheter. Shortly after abrasion, theCoFs of the abraded catheters were measured.

For the dry-out CoF measurement, the each tubing was hydrated in waterfor 30 seconds and then placed in a controlled atmosphere with aconstant relative humidity of 50% RH and a constant temperature of 23°C. for 10 minutes prior to measuring the CoF.

Table 12 shows a summary of the CoF results for tubings H-N and the typeof photoinitiator that was used in the coating.

TABLE 12 10 Min. Tubing Initial Abraded Dry-out Sample CoF CoF CoFPhotoinitiator H 0.012 0.072 0.021 Esacure One I 0.032 0.061 0.043Benzophenone J 0.016 0.026 0.023 Esacure One K 0.014 0.014 0.036 EsacureOne L 0.017 0.014 0.026 Esacure One M 0.030 0.030 0.044 Benzophenone N0.028 0.029 0.046 Benzophenone

Swelling Measurements

A sample of each of the uncoated tubing J-N were weighted in amicrobalance and then immersed in a bath of water at 70° C. for 24hours. The tubings were then removed from the bath of water and weight.For each tubing sample, the initial weight of the tubing and the weightafter immersion were compared to determine the percentage of wateruptake, the results of which are reported in Table 13 of the weremeasured after 24 hours of immersion in water.

TABLE 13 Water Tubing Uptake Sample [%] J 1.05 K 0.46 L 3.26 M 2.38 N2.15

Example 5

The below hydrophilic coating was formed on tubing Samples M and N. Thehydrophilic coatings were applied directed to the surface of the tubingwithout using a primer coating/layer and without pre-treating thesurface of the tubing. The hydrophilic coating was applied directly tothe surfaces of the catheters by dip coating.

The hydrophilic coating composition/formulation was prepared with thecomponents as shown in the table below.

TABLE 14 Component Amount (w/w) Ethanol (absolute) (Lennox) 78.99%(w/w)  De-ionized water (Lennox) 14.00% (w/w)  PVP K90 (Ashland) 5.95%(w/w) BHT-A (Sigma Aldrich) 0.01% (w/w) PEG400DA (SR344, Sartomer,inhibitor removed) 0.30% (w/w) Glycerol 0.74% (w/w) Benzophenone 0.01%(w/w)

The hydrophilic coating composition was prepared by adding PVP to theethanol and water and mixing until dissolved. The remaining components(glycerol, PEG400DA, BHT-A, and benzophenone) were then added andallowed to fully dissolve under stirring.

To form the hydrophilic coating on the outer surfaces of the catheters,the catheters were then immersed in the hydrophilic coating compositionfor 90 seconds and withdrawn at a rate of 0.9 cm/sec. The hydrophiliccoating composition was then UV cured and dried under UV lamps for 6.4minutes to form the hydrophilic coating on the catheter.

The initial, abraded and 10-minute dry-out CoFs were measured in thesame manner as described about. The results of which are shown in Table15 below.

TABLE 15 Initial Abraded 10 Min CoF CoF Dry-out Sample Set Avg. Avg.Avg. M 0.029 0.029 0.035 N 0.026 0.030 0.035

From the foregoing it will be observed that numerous modifications andvariations can be effectuated without departing from the true spirit andscope of the novel concepts of the present invention. It is to beunderstood that no limitation with respect to the specific embodimentsillustrated is intended or should be inferred. The disclosure isintended to cover by the appended claims all such modifications as fallwithin the scope of the claims.

What is claimed is:
 1. A urinary catheter, comprising: a catheter tubewherein at least a portion of the catheter tube is made from a blendcomprising (a) an ethylene and/or propylene based polymer with densityless than or equal than 0.95 g/cm³ and (b) a water-swellable polymer;the blend comprising between 80 wt % and 95 wt % of the ethylene and/orpropylene based polymer and between 5 wt % and 20 wt % of thewater-swellable polymer, wherein the blend defines an outer surface ofthe catheter tube which has a surface energy of at least 30 mN/m; and ahydrophilic coating disposed on at least a portion of an outer surfaceof the catheter tube, wherein the hydrophilic coating is bonded to theouter surface of the catheter tube without the formation of aninterpenetrating polymer network and wherein the hydrophilic coatingcomprises a single layer in direct contact with the outer surface of thecatheter tube.
 2. The urinary catheter of claim 1 wherein the outersurface of the catheter tube includes polar groups bonded to thehydrophilic coating.
 3. The urinary catheter of claim 1 wherein thewater-swellable polymer comprises a polymer or co-polymer selected fromthe group consisting of ethylene vinyl alcohol copolymer, polyvinylalcohol, polyether block amide and thermoplastic polyurethanes.
 4. Theurinary catheter of claim 1 wherein the water-swellable polymercomprises ethylene vinyl alcohol copolymer.
 5. The urinary catheter ofclaim 4 wherein the ethylene vinyl alcohol copolymer comprises betweenabout 20 wt % and about 50 wt % ethylene and about 50 wt % and about 80wt % vinyl alcohol.
 6. The urinary catheter of claim 1 wherein thewater-swellable polymer comprises polyvinyl alcohol.
 7. The urinarycatheter of claim 1 wherein the water-swellable polymer comprisespolyether block amide.
 8. The urinary catheter of claim 1 wherein thewater-swellable polymer comprises thermoplastic polyurethane.
 9. Theurinary catheter of claim 1 wherein the ethylene and/or propylene basedpolymer comprises copolymers of ethylene and an alpha-olefin.
 10. Theurinary catheter of claim 9 wherein the alpha-olefin is selected fromthe group consisting of 1-butene, 1-hexene and 1-octene.
 11. The urinarycatheter of claim 9 wherein the alpha-olefin comprises 1-octene.
 12. Theurinary catheter of claim 1 wherein the blend further includes acompatibilizer.
 13. The urinary catheter of claim 12 wherein thecompatibilizer is an acid modified polyolefin in an amount of betweenabout 5 wt % and about 20 wt % of the blend.
 14. The urinary catheter ofclaim 1 wherein the hydrophilic coating comprises polyvinylpyrrolidone.15. A urinary catheter, comprising: a catheter tube wherein at least aportion of the catheter tube is made from a blend comprising (a) anethylene and/or propylene based polymer with density less than or equalthan 0.95 g/cm³ and (b) a water-swellable polymer; the blend comprisingbetween 80 wt % and 95 wt % of the ethylene and/or propylene basedpolymer and between 5 wt % and 20 wt % of the water-swellable polymer,wherein the blend defines an outer surface of the catheter tube whichhas a surface energy of at least 30 mN/m; a hydrophilic coating disposedon at least a portion of an outer surface of the catheter tube, whereinthe hydrophilic coating is bonded to the outer surface of the cathetertube without the formation of an interpenetrating polymer network; andwherein there is no primer layer between the outer surface of thecatheter tube and the hydrophilic coating.
 16. The urinary catheter ofclaim 15 wherein the outer surface of the catheter tube includes polargroups bonded to the hydrophilic coating.
 17. The urinary catheter ofclaim 15 wherein the water-swellable polymer comprises a polymer orco-polymer selected from the group consisting of ethylene vinyl alcoholcopolymer, polyvinyl alcohol, polyether block amide and thermoplasticpolyurethanes.
 18. The urinary catheter of claim 15 wherein thewater-swellable polymer comprises ethylene vinyl alcohol copolymer. 19.The urinary catheter of claim 18 wherein the ethylene vinyl alcoholcopolymer comprises between about 20 wt % and about 50 wt % ethylene andabout 50 wt % and about 80 wt % vinyl alcohol.
 20. The urinary catheterof claim 15 wherein the water-swellable polymer comprises polyvinylalcohol.
 21. The urinary catheter of claim 15 wherein thewater-swellable polymer comprises polyether block amide.
 22. The urinarycatheter of claim 15 wherein the water-swellable polymer comprisesthermoplastic polyurethane.
 23. The urinary catheter of claim 15 whereinthe ethylene and/or propylene based polymer comprises copolymers ofethylene and an alpha-olefin.
 24. The urinary catheter of claim 23wherein the alpha-olefin is selected from the group consisting of1-butene, 1-hexene and 1-octene.
 25. The urinary catheter of claim 23wherein the alpha-olefin comprises 1-octene.
 26. The urinary catheter ofclaim 15 wherein the blend further includes a compatibilizer.
 27. Theurinary catheter of claim 26 wherein the compatibilizer is an acidmodified polyolefin in an amount of between about 5 wt % and about 20 wt% of the blend.
 28. The urinary catheter of claim 15 wherein thehydrophilic coating comprises polyvinylpyrrolidone.